In Flagrante Delicto
by theflexibledetective
Summary: AU set during After the Storm. In flagrante delicto: 1.: in the very act of committing a misdeed, 2. in the midst of sexual activity. Beckett and Castle are a little wrapped up in each other after their first night together, and don't notice Martha and Alexis arriving home. This new relationship of theirs sure isn't a secret for long!


**A/N: I loved how the morning after was dealt with in _After the Storm_, but I thought it might be a little giggle-worthy to imagine what would've happened if Martha & Alexis caught them in the act. I tried to stay as true to character/dialogue as possible. Hope you enjoy!**

* * *

"So, what do you want to do today? Castle asked dazedly as he watched Beckett slowly unbutton his shirt she was wearing.

"I don't know...we could read..."

He liked this little game. He slid the shirt off her shoulder, trying not to gape when her breast popped into view. Last night he had seen them, but it was dimly lit in his bedroom. Now, with the bright sunshine streaming into the room, he marvelled at the gloriousness that was Katherine Beckett's breast. He had the urge to pop her delicious looking pink nipple into his mouth, but he wanted to play her teasing game just a little longer.

"We could watch TV," he said. The only thing he planned to do was watch her, while he was over her, under her, beside her, and between her. He wanted to make her smile when he cooked them breakfast, lunch, and dinner. He wanted to drip honey between her breasts and down her stomach and in her belly button and feel her squirm when he licked it away. There were a million things that he was going to do to her today and he was overjoyed that these were no longer fantasies he needed to indulge himself in to make it through the day or night. She was finally his, and he was going to make sure she stayed that way.

"Yeah," Beckett said, getting a little breathless, "we could get something to eat..."

She trailed off as she leaned closer to his lips, smiling. It had been a long time since Kate had been this deliriously happy. Their lips met in a sweet little kiss and Beckett couldn't help but giggle a little at how _well_ this was going already. Even though they had already had sex three times and they barely got any sleep whatsoever, Beckett could feel herself already ready for round four. Castle clearly was on the same page as her as he deepened the kiss and pulled her on top of him. He was the first to pull away from the kiss, and Beckett stared down at him as he pulled the shirt he was wearing down off her other shoulder so that both of her breasts were bared. He took them both in his hands and thumbed her nipples, loving the way they both got stiff and stood at attention. Beckett shifted on his lap and he sat up to take one of them in his mouth.

Beckett let out a soft shriek when he bit down on one. He laved the little bud with his tongue, and used his other hand to trail downwards, parting her lips with his fingers, and seeking that other little bud that had her screaming last night. She shivered when his fingers brushed her clit. He was only a little surprised to find she was already wet and aching for him. They both shifted back just a little so that Castle could guide his cock into her, and when he did, Beckett wrapped her legs around his waist and he wrapped his arms around hers, and they pulled each other closer.

It was sensuous, this kind of lovemaking. Last night was all about apologies, the frantic thrusts and the teeth scraping against skin and the hotly whispered words in each other's ears. Today was all about promises, the soft morning kisses and the fingers memorizing paths on each other's skin and the gentle movements to make up for the roughness of the night before. They rocked together slowly. Neither of them would be able to come like this but both were enjoying the intimacy too much at the moment to care.

Castle started a rhythm on her clit with his fingers that had Beckett gasping and shifting her hips on his lap. Finally, when it became too much, she pushed him back against the pillows and began to ride him in earnest, desperately seeking release.

"_Fuck_, Kate...yes, Kate." had become his mantra over the course of the last twelve hours. He could only see her, could only think of her. She was fucking him both blind and stupid, and he absolutely couldn't be fucked to care.

"Oh god, Castle. Please, Rick," had become hers. She alternated between his first and last name, her brain too overloaded with pleasure to differentiate between the two, and he loved watching her fall apart.

The two of them were so lost in their passionate search for release that neither of them heard the front door open and close.

Martha guided Alexis to the kitchen chairs, and sat her down on one, too concerned over the state of her granddaughter and too far away from Richard's bedroom to notice the soft sounds coming from it.

* * *

"Now you sit down here. Do you want me to make you some tea? Tea can be very soothing."

"No, no tea." Alexis said, and laid her face down on the cool granite countertop.

"No tea," Martha echoed.

"Ugh, my head is pounding," Alexis said miserably. At fifteen she had scolded her dad for trying to get her to drink champagne. She never imagined that she'd be so hungover at eighteen that she'd had to call her Grams to pick her up so she could vomit at her own home in privacy.

"I'll go get you an aspirin, darling, you just wait here."

"Mmm," Alexis mumbled, and tried to think of anything but her churning stomach.

Martha was too busy making a list of things to do to help Alexis feel better that she flew into Richard's room unthinkingly to grab some aspirin from his medicine cabinet. She halted in her tracks.

"Oh god!" she exclaimed.

Beckett screamed in surprise, and tried to roll off Castle. Instead, the two of them gracelessly rolled off the bed and on to the floor with a loud bang. She grabbed a pillow from the bed to cover herself because Rick had stolen the sheet and had wrapped it around himself. How noble, she thought sardonically.

"Martha!" Beckett exclaimed just as Castle said "Mother!"

Both of them stood awkwardly, looking not unlike two highschoolers that had been caught in the act by their parents. It would have been comical had they not been totally embarrassed. Beckett was pretty sure she couldn't blush any harder than she already was. The three of them stared at each other awkwardly, until Castle finally broke the silence.

"Mother, what are you doing home?"

After the initial shock had worn off, Martha was beaming. "Well, the graduation festivities got a little out of hand, and Alexis had called, asking to be picked up, so I drove back into town. I just didn't expect you to have _company_"

Beckett was too mortified to think of anything particularly clever to say, so she kept her mouth shut, but Castle had little alarm bells ringing in his head.

"Alexis is here too?" he asked. Martha just shrugged and nodded. As if his nightmare couldn't possibly be getting any worse, at that moment, Alexis shuffled into his bedroom.

"Grams, what's going on, I thought I heard-" Alexis froze as she took in the scene. All three adults stared at her, trying to decipher her reaction. Alexis heaved once, perhaps due to the large quantity of alcohol she had consumed the night before or perhaps due to the fact that she had walked in on her father practically _in flagrante delicto_, so to speak, no one would ever know. She managed to gasp, "I'm going to throw up," before she clamped a hand over her mouth and bolted for the toilet.

"Sweetheart, are you okay?" Castle called after her. He made a move towards the bathroom, and, noticing that he was still only wearing a sheet, decided that may not be the best idea and stayed where he was.

"Perhaps it'd be better if you got dressed…" Martha said.

"Uh, right," Castle said, and bolted for the closet.

Beckett managed to push her embarrassment down and straightened. "Martha, I'm so sorry, it's just -"

"Nonsense dear! I am thrilled for you and Richard. You must excuse me; you just caught me off guard!"

"Yeah, you and me both," Beckett muttered. She started searching around the room for her discarded clothing, still clutching the pillow to her chest. Castle's shirt had remained on during their…_activities_, and luckily it skimmed the middle of her thighs and covered the bits that the pillow didn't reach_._

"Here, dear, you can use my room to get changed," Martha said.

Beckett had her clothes bundled under her arm. "Thank you," she said gratefully, and turned to head upstairs.

"Katherine?" Martha said. Beckett turned and noticed Martha holding out her little black lace striped bra. She flushed a bright red once again, and snatched it from Martha's fingertips.

"Thanks," she said, and rushed out the door.

* * *

Beckett made it home in twenty minutes – a personal best. She couldn't have run out of Castle's place faster if there was a bomb sitting in the middle of his living room. She had hastily called out a few apologies as she bolted, telling herself that the reason she was leaving was because she wanted to give Castle some time to help his daughter get better.

It was almost lunchtime when Castle knocked on her apartment door. She had a feeling it was him before she even reached the peep-hole. Beckett had had a long bath when she'd gotten home and was feeling much more relaxed but still just as embarrassed. When she opened the door, Castle had a comically wary look on his face.

"I am _so_ sorry about that," he said. Beckett rolled her eyes and smiled, stepping back into the apartment to let him in.

"Yeah, that definitely wasn't our finest hour," she admitted. "How's Alexis?"

"I don't know…after she finished throwing up she wasn't exactly verbose. I left her sleeping on the couch. Mother's promised to look after her tonight."

"Ah, and how is Martha?"

"Are you kidding? She's practically been planning our wedding since I first started working with you. Not that I'm expecting us to get married or -" Castle said hastily. Beckett stopped him with a kiss.

"It's alright, Castle. Martha did always have that look in her eye every time I came over. But, maybe just for a little while I'll be avoiding your place…"

"Yeah, well, four's a bit of a crowd. Maybe we could just stay here for awhile…" Castle said, stepping closer to Beckett.

"Yeah…that sounds good. We did get interrupted earlier…I wouldn't mind finishing off round four…"

"Maybe we could even make it to round five…" Castle said, and tilted her face up towards him so he could give her a kiss. Before their lips had a chance to brush, there was a knock at the door.

"They're stalking us," Castle said, horrified. Beckett rolled her eyes.

"Who is it?"

"Beckett, its Ryan!"

Beckett's eyes got wide. "Quick, hide! Over there, in the closet."

"Wait, what? Why should I hide?" Castle said. "Unless…you're embarrassed to be seen with me! That's why you ran out of my place so fast! You don't want anyone to know because you don't want to admit to being with the plucky sidekick!"

"What? That's…no. That's not true. It's just…maybe I want to keep this between us, for now."

"Mother and Alexis already know," Castle said petulantly. Beckett raised her eyebrow.

"Yeah, you think it might be a little different when Ryan and Espo find out? Which could be soon if you don't _hide_?"

"Beckett, is everything okay in there?" Ryan called.

"Fine!" Beckett yelled. She looked back at Castle expectantly.

"They're not going to find out," Castle said.

"You're at my apartment!"

"Yes, but I still have my _clothes on_."

Beckett sighed, and realized she wasn't going to win this battle. She hoped Detective Ryan wasn't feeling particularly keen today.

"Okay, fine. Just…act normal. If that's even possible for you."

"It's me!" Castle tried to sound offended, but he got a little distracted by the way Beckett's ass looked as she walked away from him to answer the door,

For now, he plotted how to get Ryan out of the apartment as quickly as possibly so he could do exactly what he wanted to with Beckett for the rest of his day.

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**Any sort of constructive criticism is most welcome :)  
****Please review and let me know what you think!**


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